<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>内边距、外边距</title>
    <style>
        .one {
            border: 2px blue solid;
            width:100px;
            height:50px;
            padding: 10px;
        }
        .two {
            border: 2px green solid;
            width:50px;
            height:20px;
            
        }
    </style>
</head>
<body>
    <div class = "one">
        <div class="two">444</div>
        <div class="two">555</div>
    </div>
    <div class = "one">222</div>
    <div class = "one">333</div>
</body>
</html>